This invention relates generally to lightning strike protection, and more specifically, to fabrication and installation of preformed dielectric inserts.
There are thousands of recessed fasteners in a typical aircraft surface. In one aircraft wing example, these fasteners penetrate from the skin exterior and extend into the fuel tank. One currently contemplated fabrication plan is application of an uncured sealant over the fasteners as part of an integrated lightning strike protection system. The sealant is cured in place, then shaved with a cutter to flushness with the surrounding wing skin. In composite aircraft structures, the sealant functions as a dielectric insulating layer, insulating the fasteners from lightning strikes.
Mechanical devices with reciprocating metal blades are known, and utilized to shave an upper portion of a cured in place dielectric sealant material such that it is substantially flush with a surface. However, these devices cannot be utilized in certain production environments. In one example, the number of places to be shaved in a given area may preclude use of the mechanical device. In another example, the surface where the sealant has been placed may be contoured, which also may not be easily compatible with the described shaving process.
The above described process is labor intensive, and the in-place curing and shaving of dielectric sealant may effect aerodynamic dimensional tolerances. Another issue is that sealant application is an integral step in the assembly process rather than prior to or concurrent with the assembly process (i.e., more labor, time, and interference with other production steps). Accordingly, there is continued effort in the art for improvement in regard to installation of dielectric materials in certain applications.